1. Field of Invention
The present invention relates to a container closure and more particularly to an improved tear-off closure and a method of forming such closure having an integral, concentric pull ring for manually removing the closure from a container on which it is sealed. The pull ring on the closure of the present invention is formed such that the ring is held in a fixed position at the bottom of the closure prior to sealing of the closure on a container.
2. Description of the Prior Art
A tear-off closure having an integral concentric pull ring for removing the closure from a container is described in U.S. Coop Pat. No. 3,865,268. The closure disclosed in that patent has an integral skirted cap wall depending from the periphery of a cap top and a curled bead which forms a pull ring around the closure skirt. The pull ring is connected to the closure skirt through a sever line provided by either a score line or slits and bridges adjacent the bead at the bottom of the cap wall. Such connection of the pull ring to the closure skirt secures the ring in position on the closure prior to sealing of the closure on a container at which time the sever line is broken or severed. The secured position of the pull ring on the closure prior to capping facilitates handling and hoppering of the closures as is necessary to bring them into position for capping a container.
Although a score line or slits and bridges in the sever line in the closure disclosed in U.S. Pat. No. 3,865,268 usually works well, such sever line is sometimes accidentally broken during forming of the closure. The score line or slits and bridges must usually be formed prior to forming of the curled bead and may be prematurely broken or severed during such curling. Additionally, upon capping of a container with a closure of U.S. Pat. No. 3,865,268, the ruptured edges of the score or bridges on the pull ring may sometimes project from the ring in such a way as to pose a risk of cutting the fingers of the consumer.
Accordingly, an improved tear-off closure, and method of forming the same, is desired which will assure that the pull ring remains peripherally attached around the base of the closure skirt prior to the capping operation and also assures safe removal of the closure from a container on which it is applied.